During the winter months in the Rockies, Midges are the primary hatching insect found throughout the region. A basic understanding of their lifecycle and each stage of the organism’s vulnerability to trout can quickly help “stack the deck” in the fly-fisherman’s favor. Matching fly patterns with imitations of the various Midge lifecycles - fishing them with appropriate techniques will certainly increase an angler’s success while fly-fishing in the Bozeman area during the winter months.

Larvae

The larval stage is the most prolific stage in a Midge’s lifecycle with multiple generations all being available to trout at any one given time. They essentially look like very small worms, stay close to structure, and thrive in areas along our Bozeman fly-fishing with slow current and silty bottoms.

These are best fished subsurface with weight either on the fly or by adding split shot to a leader. The most common fly-fishing technique to effectively fish larvae patterns is under a strike indicator on a tapered leader – the depth and amount weight needed will depend on the water you are fishing. A great setup to start with is a 9’ 5x leader with a strike indicator about 5-6 feet from the first fly (some type of generalist nymph pattern like a prince nymph, pheasant tail, or egg variation) with the Midge larvae pattern tied on 12-18” of 5x tippet off the bend or eye of the first fly. Add weight in the form of split shot (anywhere from a #1-BB size is generally required for the waters around Bozeman) placed on the leader, about 18” above the first fly.

Favorite Midge Larvae Patterns for Fly-Fishing near Bozeman

Pupae

The pupae stage of a Midge’s lifecycle is the most important from and angler’s perspective as they are readily available to Trout as they drift through the current and water column. Adults emerge from the pupae stage in a relatively slow process during which the pupae are often stuck in the water tension at the surface. Trout will feed on pupae patterns both on the surface and subsurface as well.

Fly-fishing with weighted nymphs rigs under a strike indicator that include a pupae pattern can be very effective during hatch periods of a Midge hatch. Pupae pattern can also be fished as a dry or wet fly just under the surface while targeting slowly rising trout or their rise-forms during a hatch. A long, tapered leader in the 10-12’ length range with 5x tippet and a single pupae pattern can be very challenging as the pupae patterns tend to sit low on the water and are difficult to pick out from the naturals – sometimes fishing these as a dropper tied off the bend of a more visible dry fly such as a Parachute Adams or Hi-Viz Griffith’s Gnat can make all the difference in detecting strikes on pupae patterns.

Favorite Midge Pupae Patterns for Bozeman Fly-Fishing

Adults

The adult stage of a Midge’s lifecycle is short-lived for the organism but the most fun for both trout and angler. During large emergences - which typically take place on mild, humid, cloudy days - the water’s surface will be covered with large masses of hatching adults. They quickly accumulate in back-eddies and soft-water seams in large masses of what are often described as mating clusters. Trout will readily rise to flies that imitate these clusters, so fishing a fly that is imitative of a single adult Midge is rarely required except on the most selective spring creek trout.

Long leaders in the 10-12’ range with 5x or 6x are the typical “go-to” rig when dry fly fishing during a Midge hatch on the various Bozeman fly-fishing waters. Patterns that are easy to see, well hackled, and perhaps also have some CDC on them are great places to start once the angler sees the adults on the water and trout actively feeding on the surface. A specialty fly line like the RIO Technical Trout or Scientific Anglers Trout tapers help turn these long leaders over for delicate presentations much more efficiently than a standard fly line and are worth the investment as the angler’s skills improve.

Favorite Midge Adult Patterns for Bozeman Fly-Fishing

Midges can come in a wide range of colors from white to bright red and everywhere in between. Standard nymph colors are red, olive, and black (zebra) while the dries typically have bodies that are gray, peacock, or black in color with light colored hackle for wings. While the actual insect size might be as small as #28, fly sizes most used effectively are #18-#20.

Our Bozeman fly-fishing guide service offers trips year-round and booking a day with one of our guides is a great way to learn more about the local Midge fly-fishing options. Reservations can be booked directly online or e-mail us for more information as well.